The opening moments of “After the Murder of Albert Lima” are where the confusion begins. A Tampa area personal trainer is talking to a couple living on an island in the Caribbean. He puts them on speaker phone.

He’s asking about borrowing guns. They’re offering to give him Haldol so that he can knock somebody out. Maybe they’ll even do the injecting themselves. He mentions plans to “stuff (their quarry) in a suitcase.”

Hells’ bells, what criminal mischief are these rubes cooking up? I mean, “Murder of Albert Lima” is billed as a documentary. Are we watching a mockumentary?

It’s not, though. Filmmaker Aengus James has been invited to listen in as a bunch of amateurs work out the logistics of something that “the movies” make look simple, easy — especially when the “professionals” do it.

But the “professionals” here, a “tracker” (Art Torres) and a “bounty hunter” (Zora Colakovic) project the confidence of the delusional. In their own minds, they’ve got this. But we can sense it in their bravado, signs we recognize in the daily public (political) examples of “the very best people” who cannot hide their rank incompetence.

We can meet Paul Lima, the personal trainer setting this caper in motion, and hear his story. It’s the tragic account of the murder of his Tampa lawyer father on the lawless Honduran island of Roatán (“paradise” for scuba divers, among others). We can see the grisly crime-scene photos, a man shot and dumped in the woods in a place where even if the police cared, they’re ill-equipped to bring the killers to justice.

Paul can tell us of his 13-year quest for justice, the corrupt Honduran court system that let the killer go free for the right bribe. We can hear about accomplices, one of them a friend of his father, killed, and of the good-faith loan (to keep a bakery open) that went bad and triggered all this.

But at the end of the day, ordinary people trying to get justice or revenge or closure on their own, or providing that as a paid service that they’re ill-equipped to deliver, is damned funny.

It’s what the talk show host/philosopher Steve Allen said — “Tragedy plus time equals comedy.” Time has passed. And there is nothing funnier than delusions of competence.

There are fraught moments, secret cameras trying to capture efforts to get close to the killer, Oral Coleman. Paranoid men with pistols and shotguns stand between our team and their quarry. The American couple, the Krims, who want to help, are under death threats themselves. The island is overrun with unsolved murders of Americans.

But when your personal trainer-leader is talking about how they will “‘Weekend at Bernies’ this guy,” when he’s trying to hire a charter fishing boat to smuggle them all to the mainland (on camera) and NOT telling the captain what they’re really up to, with every moment this conspirator or that one dons his “C.S.I.: Miami” sunglasses, with every stakeout that ends with one of the “professionals” getting drunk and passing out, with every accidental discharge of a gun, “After the Murder of Albert Lima” becomes less tragic, more farcical.

“Rookie mistake,” one character will admit. “We’re not prepared for this” another finally confesses.

Filmmaker James has to be lumped in with everybody else, as his filming and “crew” give the would-be kidnappers cover. They’re all making “like a National Geographic kind of documentary.” If this comes off, or goes wrong, there will be blood on James’ hands, too. Or egg on his face.

Fake accents are trotted out for phone calls, nothing goes off “like clockwork” because in the real world life is messy and random, unscripted and not routine.

I’d love to get a gander at the release forms James cooked up for this project. Because as sincere as one and all are — especially Paul, who seems genuinely gutted and often outraged by his inability to get justice (he even got Congress to authorize money to have murders of Americans in Honduras investigated and prosecuted) — the payoff is a movie in which everybody comes off, at least at times, as an idiot.

And good sports or not, who’d agree to let a movie show them in that light?

MPAA Rating: unrated, violent images

Cast: Paul Lima, Art Torres, Zora Colakovic, Cindy Krim, Kent Krim, Judy Lima

Credits: Directed by Aengus James. A Gunpowder & Sky release.

Running time: 1:37